空間外部性、交易成本與市地重劃對住宅土地價格影響之研究──台南市的實證分析

The Impact of Spatial Externalities, Transaction Costs and Land Readjustment on Residential Land Prices-Evidence from Tainan City

本文主要從政府實施市地重劃有助於降低交易成本的觀點，探討政府實施市地重劃制度及建設商的土地開發行為所產生的空間外部性，其反應在住宅土地價格的影響。本文運用空間計量分析及地理資訊系統，並結合Box-Cox函數轉換，以建構具有空間外部性的特徵價格模型。本文研究範圍以台南市民國八十年、八十五年及九十年的新建住宅為對象。實證結果得知，空間誤差Box-Cox模型對於空間外部性提供良好的解釋力。政府實施市地重劃之後對住宅土地價格具有正向外部性，且有政府參與的重劃區所反應的住宅土地邊際價格為正向關係。而建設商個體互動關係則具有正向及負向外部性，並在長期下出現由正向轉為負向之情況，此證明空間外部性會呈現相互性的現象，進而反應在住宅土地價格上會有增減的作用。

This paper mainly assumes that land readjustment can reduce transaction costs in terms of the spatial externalities from developers' behavior and the institution of land readjustment. Finally, this effect will be reflected in the residential land prices. To test this hypothesis, I apply spatial econometric analysis and geographic information systems based on the Box-Cox hedonic pricing model. The data are selected from newly-built residences from between 1991, 1996 and 2001 in Tainan City in Taiwan. Empirically, I find that the spatial error Box-Cox model is appropriate for engaging in spatial externalities analysis. This is because the results show that land readjustment gives rise to positive spatial externalities on residential land prices and the marginal price of residential land in areas where land readjustment takes place is also positive. The effects of developers' interactions give rise to positive spatial externalities but these change to negative spatial externalities in relation to residential land prices in the long term. Finally, land readjustment as implemented by the government really does contribute to reducing uncertainty in the land development process, and also reduces transaction costs between construction practitioners and landlords.